Xuzhou Mining Project: Duplex Backwash Filtration System for Mine Water Supply and Gasification

Project Background

• Xuzhou Mining Group is a significant energy production base in China, where water quality management is critical in coal mining and deep processing sectors.
• Cooling systems for underground tunnel borers and shearers, as well as surface dust suppression systems, have strict requirements for raw water cleanliness.
• Mine water typically contains coal fines, sand, and mineral scales, requiring traditional filters to shut down for cleaning, severely hindering production efficiency.
• XMC introduced Unite’s duplex backwash filtration system to ensure 24/7 continuous operation.

Core Challenges

1. Zero Downtime: Once mining begins, a water interruption can lead to equipment overheating or excessive dust, necessitating a 100% continuous filtration process.
2. Heavy Impurity Load: Mine water contains significant amounts of hard coal chips and suspended solids, quickly saturating screens and demanding a frequent, efficient cleaning mechanism.
3. Harsh Environments: Underground operations are cramped and humid, requiring filtration equipment that is compact, rugged, and easy to operate manually or semi-automatically.
4. Nozzle Protection: Spray heads have small apertures, so the filter must stably intercept micro-particles larger than 100-200μm.

Solution

• Duplex Parallel Structure: The system consists of two independent filter vessels connected by a three-way changeover valve set, enabling one barrel to filter while the other remains on standby, allowing cleaning without stopping the flow.
• Backwash Regeneration: Equipped with high-strength stainless steel wedge wire screens, utilizing system pressure or an external source for reverse flow to quickly flush coal fines and impurities from the screen's inner wall into the drain.
• Wear & Corrosion Resistance: Vessels are made of thickened carbon steel with heavy-duty anti-corrosion coatings or stainless steel, ensuring longevity in humid and corrosive mine environments.
• User-Friendly Monitoring: Filter barrels are equipped with differential pressure gauges to alert operators for manual or semi-automatic backwash switching, with a compact design facilitating installation in narrow underground chambers.

Customer Value & Results

• The duplex backwash filters have completely resolved production interruptions caused by filter clogging at XMC, reducing the nozzle failure rate for shearer cooling systems by 85% and significantly decreasing maintenance costs.
• Online changeover and backwash capabilities have reduced manual screen cleaning frequency from multiple times per shift to once-daily inspections, drastically lowering labor intensity.
• XMC highly commended the practicality and durability of the solution, expanding its use across multiple mining districts.